Vertical deflection circuit

Abstract

A synchronous switched vertical deflection circuit for use with a television receiver comprises first and second bidirectional switches coupled to conduct current in opposite directions. Horizontal rate energy is coupled into one end of the switches. Vertical deflection means are connected to the other end of the switches. Pulse-width modulated signals are applied to the control terminals of the switches to allow conduction of the horizontal rate energy in the vertical deflection means during selected portions of each vertical deflection interval.

What is claimed is: 
     
       1. A vertical deflection circuit for use in a television receiver, comprising: first and second bidirectional switches, each comprising: a controllable switch element and a control terminal electrically connected thereto; said first and second bidirectional switches electrically connected in series with said controllable switch elements being coupled to conduct current in opposite directions through said switches;   a source of horizontal deflection rate energy coupled to one end of said bidirectional switches;   vertical deflection means including a vertical deflection coil coupled to the other end of said bidirectional switches; and   a source of pulse-width modulated signals, coupled to said control terminals of said first and second bidirectional switches, for controlling the conductivity of said controllable switch elements in such a manner as to permit conduction of said horizontal rate energy through said first and second switches into said vertical deflection means for a predetermined duration of each vertical deflection interval.   
     
     
       2. The arrangement defined in claim 1, wherein each of said bidirectional switches comprises an SCR coupled in parallel with a diode. 
     
     
       3. The arrangement defined in claim 1, wherein the duration of said pulse-width modulated signals controls the conduction duration of said bidirectional switches, the conduction of said respective first and second bidirectional switches dependent upon the polarity of the voltage component of said horizontal rate energy. 
     
     
       4. The arrangement defined in claim 1, wherein said source of pulse-width modulated signals produces a first and second plurality of signal pulses, said first plurality of signal pulses progressively decreasing in duration during said vertical deflection interval, said second plurality of signal pulses progressively increasing in duration during said vertical deflection interval. 
     
     
       5. The arrangement defined in claim 4, wherein said first plurality of signal pulses controls the conduction of said first bidirectional switch, and said second plurality of signal pulses controls the conduction of said second bidirectional switch. 
     
     
       6. A vertical deflection circuit for use in a television receiver comprising: a vertical deflection coil;   a source of vertical deflection voltage comprising a capacitor having a first terminal at a first voltage level, and a second terminal at a reference potential level, said first terminal coupled to said vertical deflection coil;   switch means, incorporating first and second terminals, comprising: first and second bidirectional switches connected in series, each of said bidirectional switches having a controllable switch element and a control terminal coupled thereto, said switch means second terminal coupled to said capacitor first terminal;   a source of horizontal deflection rate energy coupled to said first terminal of said switch means; and   a source of control pulses, the voltage level of which is referenced to said source of vertical deflection voltage, coupled to said control terminal of each of said switch means for controlling conduction of said first and second bidirectional switches for coupling said horizontal rate energy to said source of vertical deflection voltage.   
     
     
       7. The arrangement defined in claim 6, wherein said source of control pulses comprises output means having an output terminal and a reference terminal, said output terminal coupled to said control terminal of each of said switch means, said reference terminal coupled to said capacitor first terminal via a source of voltage potential. 
     
     
       8. The arrangement defined in claim 7, wherein said source of voltage potential comprises a capacitor. 
     
     
       9. A vertical deflection circuit for use in a television receiver, comprising: vertical deflection means, including a vertical deflection coil, having first and second terminals, said first terminal coupled to a point of reference potential, said second terminal coupled to a point of floating voltage potential;   bidirectional switch means comprising first and second serially-connected bidirectional conducting switches, each of said switches having a control terminal, one end of said switch means coupled to said point of floating voltage potential;   a source of horizontal deflection rate energy coupled to the other end of said switch means; and   a source of pulse-width modulated signals, the voltage level of which is referenced to said point of floating voltage potential, coupled to said control terminals of said switches for controlling conduction of said switches.   
     
     
       10. The arrangement defined in claim 9, wherein said source of pulse-width modulated signals comprises output means having an output terminal and a reference terminal, said output terminal coupled to said control terminal of each of said bidirectional switches, said reference terminal coupled to said point of floating voltage potential via a source of voltage potential. 
     
     
       11. The arrangement defined in claim 10, wherein said source of voltage potential comprises a capacitor.